Project Summary/Abstract Center for Open Science RFA-AG-19-015 The Center for Open Science (COS) will soon complete our NIH-supported grant to establish reproducibility networks to advance open practices (Phase 1). In Phase 1 COS engaged research stakeholder networks to establish and market three products to accelerate reproducibility in the social and behavioral sciences: (1) badges to acknowledge open practices (Kidwell et al., 2016), (2) Transparency and Openness Promotion (TOP) Guidelines as a policy framework (Nosek et al., 2015), and (3) Registered Reports, a publishing model in which initial peer review is conducted prior to observing the research outcomes (Nosek & Lakens, 2014). All three have contributed to substantial progress in awareness and changes in policies, incentives, and norms promoting open practices. With a 5-year grant renewal (Phase 2), COS will extend the impact of Phase 1 networks and activate new research communities to test, implement, evaluate, and improve standards and workflows to increase openness and reproducibility of research, remove barriers to behavior change, and facilitate widespread adoption of behaviors such as preregistration, and open data, materials and code. COS will deepen the level of engagement among the networks we fostered in Phase 1 and add new research networks such as the Max Planck Institute for Human Development, the Health Research Alliance and the ?International Max Planck Research School on the Life Course, to ?test, implement, evaluate, and improve the standards and supporting workflows needed to enact open science behaviors. In particular, we will accelerate adoption of preregistration and the sharing of data, materials, and code by engaging these research communities in an iterative feedback and evaluation cycle to improve the policies and workflows. While preregistration is relatively easy to apply to experimental research in which the data does not yet exist (e.g., randomized trials), preregistration workflows have yet to be created or tested to improve the rigor of observational (correlational) research, longitudinal studies, qualitative research, and working with existing datasets. These scenarios are common across a variety of disciplines, particularly aging research. And yet, translating the standards and workflows to support preregistration in such circumstances requires attention to the details of the methodology, data, and analysis pipeline (Nosek et al., 2018). COS maintains open-source infrastructure, called OSF (?http://osf.io/?), that facilitates customization of study registration workflows and submission of data, materials, and code for open or controlled sharing based on the needs of particular disciplines or methodologies. Ultimately, our efforts to organize design, test, and evaluate customized solutions with the research communities that contribute to aging research (e.g., psychology, neuroscience, sociology, political science, and epidemiology) will result in widespread adoption of open science behaviors.